1 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
3 #![feature(control_flow_enum)]
4 #![feature(try_blocks)]
5 #![feature(associated_type_defaults)]
6 #![recursion_limit = "256"]
8 use rustc_ast::MacroDef;
9 use rustc_attr as attr;
10 use rustc_data_structures::fx::FxHashSet;
11 use rustc_errors::struct_span_err;
13 use rustc_hir::def::{DefKind, Res};
14 use rustc_hir::def_id::{DefId, LocalDefId, LocalDefIdSet, CRATE_DEF_ID};
15 use rustc_hir::intravisit::{self, DeepVisitor, NestedVisitorMap, Visitor};
16 use rustc_hir::{AssocItemKind, HirIdSet, Node, PatKind};
17 use rustc_middle::bug;
18 use rustc_middle::hir::map::Map;
19 use rustc_middle::middle::privacy::{AccessLevel, AccessLevels};
20 use rustc_middle::span_bug;
21 use rustc_middle::thir::abstract_const::Node as ACNode;
22 use rustc_middle::ty::fold::TypeVisitor;
23 use rustc_middle::ty::query::Providers;
24 use rustc_middle::ty::subst::InternalSubsts;
25 use rustc_middle::ty::{self, Const, GenericParamDefKind, TraitRef, Ty, TyCtxt, TypeFoldable};
26 use rustc_session::lint;
27 use rustc_span::hygiene::Transparency;
28 use rustc_span::symbol::{kw, Ident};
30 use rustc_trait_selection::traits::const_evaluatable::{self, AbstractConst};
32 use std::marker::PhantomData;
33 use std::ops::ControlFlow;
34 use std::{cmp, fmt, mem};
36 ////////////////////////////////////////////////////////////////////////////////
37 /// Generic infrastructure used to implement specific visitors below.
38 ////////////////////////////////////////////////////////////////////////////////
40 /// Implemented to visit all `DefId`s in a type.
41 /// Visiting `DefId`s is useful because visibilities and reachabilities are attached to them.
42 /// The idea is to visit "all components of a type", as documented in
43 /// <https://github.com/rust-lang/rfcs/blob/master/text/2145-type-privacy.md#how-to-determine-visibility-of-a-type>.
44 /// The default type visitor (`TypeVisitor`) does most of the job, but it has some shortcomings.
45 /// First, it doesn't have overridable `fn visit_trait_ref`, so we have to catch trait `DefId`s
46 /// manually. Second, it doesn't visit some type components like signatures of fn types, or traits
47 /// in `impl Trait`, see individual comments in `DefIdVisitorSkeleton::visit_ty`.
48 trait DefIdVisitor<'tcx> {
51 fn tcx(&self) -> TyCtxt<'tcx>;
52 fn shallow(&self) -> bool {
55 fn skip_assoc_tys(&self) -> bool {
62 descr: &dyn fmt::Display,
63 ) -> ControlFlow<Self::BreakTy>;
65 /// Not overridden, but used to actually visit types and traits.
66 fn skeleton(&mut self) -> DefIdVisitorSkeleton<'_, 'tcx, Self> {
67 DefIdVisitorSkeleton {
69 visited_opaque_tys: Default::default(),
70 dummy: Default::default(),
73 fn visit(&mut self, ty_fragment: impl TypeFoldable<'tcx>) -> ControlFlow<Self::BreakTy> {
74 ty_fragment.visit_with(&mut self.skeleton())
76 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> ControlFlow<Self::BreakTy> {
77 self.skeleton().visit_trait(trait_ref)
79 fn visit_projection_ty(
81 projection: ty::ProjectionTy<'tcx>,
82 ) -> ControlFlow<Self::BreakTy> {
83 self.skeleton().visit_projection_ty(projection)
87 predicates: ty::GenericPredicates<'tcx>,
88 ) -> ControlFlow<Self::BreakTy> {
89 self.skeleton().visit_predicates(predicates)
93 struct DefIdVisitorSkeleton<'v, 'tcx, V: ?Sized> {
94 def_id_visitor: &'v mut V,
95 visited_opaque_tys: FxHashSet<DefId>,
96 dummy: PhantomData<TyCtxt<'tcx>>,
99 impl<'tcx, V> DefIdVisitorSkeleton<'_, 'tcx, V>
101 V: DefIdVisitor<'tcx> + ?Sized,
103 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> ControlFlow<V::BreakTy> {
104 let TraitRef { def_id, substs } = trait_ref;
105 self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref.print_only_trait_path())?;
106 if self.def_id_visitor.shallow() { ControlFlow::CONTINUE } else { substs.visit_with(self) }
109 fn visit_projection_ty(
111 projection: ty::ProjectionTy<'tcx>,
112 ) -> ControlFlow<V::BreakTy> {
113 let (trait_ref, assoc_substs) =
114 projection.trait_ref_and_own_substs(self.def_id_visitor.tcx());
115 self.visit_trait(trait_ref)?;
116 if self.def_id_visitor.shallow() {
117 ControlFlow::CONTINUE
119 assoc_substs.iter().try_for_each(|subst| subst.visit_with(self))
123 fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> ControlFlow<V::BreakTy> {
124 match predicate.kind().skip_binder() {
125 ty::PredicateKind::Trait(ty::TraitPredicate {
129 }) => self.visit_trait(trait_ref),
130 ty::PredicateKind::Projection(ty::ProjectionPredicate { projection_ty, term }) => {
131 term.visit_with(self)?;
132 self.visit_projection_ty(projection_ty)
134 ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(ty, _region)) => {
137 ty::PredicateKind::RegionOutlives(..) => ControlFlow::CONTINUE,
138 ty::PredicateKind::ConstEvaluatable(uv)
139 if self.def_id_visitor.tcx().features().generic_const_exprs =>
141 let tcx = self.def_id_visitor.tcx();
142 if let Ok(Some(ct)) = AbstractConst::new(tcx, uv) {
143 self.visit_abstract_const_expr(tcx, ct)?;
145 ControlFlow::CONTINUE
147 _ => bug!("unexpected predicate: {:?}", predicate),
151 fn visit_abstract_const_expr(
154 ct: AbstractConst<'tcx>,
155 ) -> ControlFlow<V::BreakTy> {
156 const_evaluatable::walk_abstract_const(tcx, ct, |node| match node.root(tcx) {
157 ACNode::Leaf(leaf) => self.visit_const(leaf),
158 ACNode::Cast(_, _, ty) => self.visit_ty(ty),
159 ACNode::Binop(..) | ACNode::UnaryOp(..) | ACNode::FunctionCall(_, _) => {
160 ControlFlow::CONTINUE
167 predicates: ty::GenericPredicates<'tcx>,
168 ) -> ControlFlow<V::BreakTy> {
169 let ty::GenericPredicates { parent: _, predicates } = predicates;
170 predicates.iter().try_for_each(|&(predicate, _span)| self.visit_predicate(predicate))
174 impl<'tcx, V> TypeVisitor<'tcx> for DefIdVisitorSkeleton<'_, 'tcx, V>
176 V: DefIdVisitor<'tcx> + ?Sized,
178 type BreakTy = V::BreakTy;
180 fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<V::BreakTy> {
181 let tcx = self.def_id_visitor.tcx();
182 // InternalSubsts are not visited here because they are visited below in `super_visit_with`.
184 ty::Adt(&ty::AdtDef { did: def_id, .. }, ..)
185 | ty::Foreign(def_id)
186 | ty::FnDef(def_id, ..)
187 | ty::Closure(def_id, ..)
188 | ty::Generator(def_id, ..) => {
189 self.def_id_visitor.visit_def_id(def_id, "type", &ty)?;
190 if self.def_id_visitor.shallow() {
191 return ControlFlow::CONTINUE;
193 // Default type visitor doesn't visit signatures of fn types.
194 // Something like `fn() -> Priv {my_func}` is considered a private type even if
195 // `my_func` is public, so we need to visit signatures.
196 if let ty::FnDef(..) = ty.kind() {
197 tcx.fn_sig(def_id).visit_with(self)?;
199 // Inherent static methods don't have self type in substs.
200 // Something like `fn() {my_method}` type of the method
201 // `impl Pub<Priv> { pub fn my_method() {} }` is considered a private type,
202 // so we need to visit the self type additionally.
203 if let Some(assoc_item) = tcx.opt_associated_item(def_id) {
204 if let ty::ImplContainer(impl_def_id) = assoc_item.container {
205 tcx.type_of(impl_def_id).visit_with(self)?;
209 ty::Projection(proj) => {
210 if self.def_id_visitor.skip_assoc_tys() {
211 // Visitors searching for minimal visibility/reachability want to
212 // conservatively approximate associated types like `<Type as Trait>::Alias`
213 // as visible/reachable even if both `Type` and `Trait` are private.
214 // Ideally, associated types should be substituted in the same way as
215 // free type aliases, but this isn't done yet.
216 return ControlFlow::CONTINUE;
218 // This will also visit substs if necessary, so we don't need to recurse.
219 return self.visit_projection_ty(proj);
221 ty::Dynamic(predicates, ..) => {
222 // All traits in the list are considered the "primary" part of the type
223 // and are visited by shallow visitors.
224 for predicate in predicates {
225 let trait_ref = match predicate.skip_binder() {
226 ty::ExistentialPredicate::Trait(trait_ref) => trait_ref,
227 ty::ExistentialPredicate::Projection(proj) => proj.trait_ref(tcx),
228 ty::ExistentialPredicate::AutoTrait(def_id) => {
229 ty::ExistentialTraitRef { def_id, substs: InternalSubsts::empty() }
232 let ty::ExistentialTraitRef { def_id, substs: _ } = trait_ref;
233 self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref)?;
236 ty::Opaque(def_id, ..) => {
237 // Skip repeated `Opaque`s to avoid infinite recursion.
238 if self.visited_opaque_tys.insert(def_id) {
239 // The intent is to treat `impl Trait1 + Trait2` identically to
240 // `dyn Trait1 + Trait2`. Therefore we ignore def-id of the opaque type itself
241 // (it either has no visibility, or its visibility is insignificant, like
242 // visibilities of type aliases) and recurse into bounds instead to go
243 // through the trait list (default type visitor doesn't visit those traits).
244 // All traits in the list are considered the "primary" part of the type
245 // and are visited by shallow visitors.
246 self.visit_predicates(ty::GenericPredicates {
248 predicates: tcx.explicit_item_bounds(def_id),
252 // These types don't have their own def-ids (but may have subcomponents
253 // with def-ids that should be visited recursively).
269 | ty::GeneratorWitness(..) => {}
270 ty::Bound(..) | ty::Placeholder(..) | ty::Infer(..) => {
271 bug!("unexpected type: {:?}", ty)
275 if self.def_id_visitor.shallow() {
276 ControlFlow::CONTINUE
278 ty.super_visit_with(self)
282 fn visit_const(&mut self, c: &'tcx Const<'tcx>) -> ControlFlow<Self::BreakTy> {
283 self.visit_ty(c.ty)?;
284 let tcx = self.def_id_visitor.tcx();
285 if let Ok(Some(ct)) = AbstractConst::from_const(tcx, c) {
286 self.visit_abstract_const_expr(tcx, ct)?;
288 ControlFlow::CONTINUE
292 fn min(vis1: ty::Visibility, vis2: ty::Visibility, tcx: TyCtxt<'_>) -> ty::Visibility {
293 if vis1.is_at_least(vis2, tcx) { vis2 } else { vis1 }
296 ////////////////////////////////////////////////////////////////////////////////
297 /// Visitor used to determine if pub(restricted) is used anywhere in the crate.
299 /// This is done so that `private_in_public` warnings can be turned into hard errors
300 /// in crates that have been updated to use pub(restricted).
301 ////////////////////////////////////////////////////////////////////////////////
302 struct PubRestrictedVisitor<'tcx> {
304 has_pub_restricted: bool,
307 impl<'tcx> Visitor<'tcx> for PubRestrictedVisitor<'tcx> {
308 type Map = Map<'tcx>;
310 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
311 NestedVisitorMap::All(self.tcx.hir())
313 fn visit_vis(&mut self, vis: &'tcx hir::Visibility<'tcx>) {
314 self.has_pub_restricted = self.has_pub_restricted || vis.node.is_pub_restricted();
318 ////////////////////////////////////////////////////////////////////////////////
319 /// Visitor used to determine impl visibility and reachability.
320 ////////////////////////////////////////////////////////////////////////////////
322 struct FindMin<'a, 'tcx, VL: VisibilityLike> {
324 access_levels: &'a AccessLevels,
328 impl<'a, 'tcx, VL: VisibilityLike> DefIdVisitor<'tcx> for FindMin<'a, 'tcx, VL> {
329 fn tcx(&self) -> TyCtxt<'tcx> {
332 fn shallow(&self) -> bool {
335 fn skip_assoc_tys(&self) -> bool {
342 _descr: &dyn fmt::Display,
343 ) -> ControlFlow<Self::BreakTy> {
344 self.min = VL::new_min(self, def_id);
345 ControlFlow::CONTINUE
349 trait VisibilityLike: Sized {
351 const SHALLOW: bool = false;
352 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self;
354 // Returns an over-approximation (`skip_assoc_tys` = true) of visibility due to
355 // associated types for which we can't determine visibility precisely.
356 fn of_impl(def_id: LocalDefId, tcx: TyCtxt<'_>, access_levels: &AccessLevels) -> Self {
357 let mut find = FindMin { tcx, access_levels, min: Self::MAX };
358 find.visit(tcx.type_of(def_id));
359 if let Some(trait_ref) = tcx.impl_trait_ref(def_id) {
360 find.visit_trait(trait_ref);
365 impl VisibilityLike for ty::Visibility {
366 const MAX: Self = ty::Visibility::Public;
367 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self {
368 min(find.tcx.visibility(def_id), find.min, find.tcx)
371 impl VisibilityLike for Option<AccessLevel> {
372 const MAX: Self = Some(AccessLevel::Public);
373 // Type inference is very smart sometimes.
374 // It can make an impl reachable even some components of its type or trait are unreachable.
375 // E.g. methods of `impl ReachableTrait<UnreachableTy> for ReachableTy<UnreachableTy> { ... }`
376 // can be usable from other crates (#57264). So we skip substs when calculating reachability
377 // and consider an impl reachable if its "shallow" type and trait are reachable.
379 // The assumption we make here is that type-inference won't let you use an impl without knowing
380 // both "shallow" version of its self type and "shallow" version of its trait if it exists
381 // (which require reaching the `DefId`s in them).
382 const SHALLOW: bool = true;
383 fn new_min(find: &FindMin<'_, '_, Self>, def_id: DefId) -> Self {
385 if let Some(def_id) = def_id.as_local() {
386 find.access_levels.map.get(&def_id).copied()
395 ////////////////////////////////////////////////////////////////////////////////
396 /// The embargo visitor, used to determine the exports of the AST.
397 ////////////////////////////////////////////////////////////////////////////////
399 struct EmbargoVisitor<'tcx> {
402 /// Accessibility levels for reachable nodes.
403 access_levels: AccessLevels,
404 /// A set of pairs corresponding to modules, where the first module is
405 /// reachable via a macro that's defined in the second module. This cannot
406 /// be represented as reachable because it can't handle the following case:
408 /// pub mod n { // Should be `Public`
409 /// pub(crate) mod p { // Should *not* be accessible
410 /// pub fn f() -> i32 { 12 } // Must be `Reachable`
416 macro_reachable: FxHashSet<(LocalDefId, LocalDefId)>,
417 /// Previous accessibility level; `None` means unreachable.
418 prev_level: Option<AccessLevel>,
419 /// Has something changed in the level map?
423 struct ReachEverythingInTheInterfaceVisitor<'a, 'tcx> {
424 access_level: Option<AccessLevel>,
425 item_def_id: LocalDefId,
426 ev: &'a mut EmbargoVisitor<'tcx>,
429 impl<'tcx> EmbargoVisitor<'tcx> {
430 fn get(&self, def_id: LocalDefId) -> Option<AccessLevel> {
431 self.access_levels.map.get(&def_id).copied()
434 fn update_with_hir_id(
437 level: Option<AccessLevel>,
438 ) -> Option<AccessLevel> {
439 let def_id = self.tcx.hir().local_def_id(hir_id);
440 self.update(def_id, level)
443 /// Updates node level and returns the updated level.
444 fn update(&mut self, def_id: LocalDefId, level: Option<AccessLevel>) -> Option<AccessLevel> {
445 let old_level = self.get(def_id);
446 // Accessibility levels can only grow.
447 if level > old_level {
448 self.access_levels.map.insert(def_id, level.unwrap());
459 access_level: Option<AccessLevel>,
460 ) -> ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
461 ReachEverythingInTheInterfaceVisitor {
462 access_level: cmp::min(access_level, Some(AccessLevel::Reachable)),
468 // We have to make sure that the items that macros might reference
469 // are reachable, since they might be exported transitively.
470 fn update_reachability_from_macro(&mut self, local_def_id: LocalDefId, md: &MacroDef) {
471 // Non-opaque macros cannot make other items more accessible than they already are.
473 let hir_id = self.tcx.hir().local_def_id_to_hir_id(local_def_id);
474 let attrs = self.tcx.hir().attrs(hir_id);
475 if attr::find_transparency(attrs, md.macro_rules).0 != Transparency::Opaque {
479 let item_def_id = local_def_id.to_def_id();
480 let macro_module_def_id =
481 ty::DefIdTree::parent(self.tcx, item_def_id).unwrap().expect_local();
482 if self.tcx.hir().opt_def_kind(macro_module_def_id) != Some(DefKind::Mod) {
483 // The macro's parent doesn't correspond to a `mod`, return early (#63164, #65252).
487 if self.get(local_def_id).is_none() {
491 // Since we are starting from an externally visible module,
492 // all the parents in the loop below are also guaranteed to be modules.
493 let mut module_def_id = macro_module_def_id;
495 let changed_reachability =
496 self.update_macro_reachable(module_def_id, macro_module_def_id);
497 if changed_reachability || module_def_id == CRATE_DEF_ID {
501 ty::DefIdTree::parent(self.tcx, module_def_id.to_def_id()).unwrap().expect_local();
505 /// Updates the item as being reachable through a macro defined in the given
506 /// module. Returns `true` if the level has changed.
507 fn update_macro_reachable(
509 module_def_id: LocalDefId,
510 defining_mod: LocalDefId,
512 if self.macro_reachable.insert((module_def_id, defining_mod)) {
513 self.update_macro_reachable_mod(module_def_id, defining_mod);
520 fn update_macro_reachable_mod(&mut self, module_def_id: LocalDefId, defining_mod: LocalDefId) {
521 let module = self.tcx.hir().get_module(module_def_id).0;
522 for item_id in module.item_ids {
523 let def_kind = self.tcx.def_kind(item_id.def_id);
524 let vis = self.tcx.visibility(item_id.def_id);
525 self.update_macro_reachable_def(item_id.def_id, def_kind, vis, defining_mod);
527 if let Some(exports) = self.tcx.module_reexports(module_def_id) {
528 for export in exports {
529 if export.vis.is_accessible_from(defining_mod.to_def_id(), self.tcx) {
530 if let Res::Def(def_kind, def_id) = export.res {
531 if let Some(def_id) = def_id.as_local() {
532 let vis = self.tcx.visibility(def_id.to_def_id());
533 self.update_macro_reachable_def(def_id, def_kind, vis, defining_mod);
541 fn update_macro_reachable_def(
548 let level = Some(AccessLevel::Reachable);
550 self.update(def_id, level);
553 // No type privacy, so can be directly marked as reachable.
554 DefKind::Const | DefKind::Static | DefKind::TraitAlias | DefKind::TyAlias => {
555 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
556 self.update(def_id, level);
560 // Hygine isn't really implemented for `macro_rules!` macros at the
561 // moment. Accordingly, marking them as reachable is unwise. `macro` macros
562 // have normal hygine, so we can treat them like other items without type
563 // privacy and mark them reachable.
564 DefKind::Macro(_) => {
565 let item = self.tcx.hir().expect_item(def_id);
566 if let hir::ItemKind::Macro(MacroDef { macro_rules: false, .. }) = item.kind {
567 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
568 self.update(def_id, level);
573 // We can't use a module name as the final segment of a path, except
574 // in use statements. Since re-export checking doesn't consider
575 // hygiene these don't need to be marked reachable. The contents of
576 // the module, however may be reachable.
578 if vis.is_accessible_from(module.to_def_id(), self.tcx) {
579 self.update_macro_reachable(def_id, module);
583 DefKind::Struct | DefKind::Union => {
584 // While structs and unions have type privacy, their fields do not.
586 let item = self.tcx.hir().expect_item(def_id);
587 if let hir::ItemKind::Struct(ref struct_def, _)
588 | hir::ItemKind::Union(ref struct_def, _) = item.kind
590 for field in struct_def.fields() {
591 let def_id = self.tcx.hir().local_def_id(field.hir_id);
592 let field_vis = self.tcx.visibility(def_id);
593 if field_vis.is_accessible_from(module.to_def_id(), self.tcx) {
594 self.reach(def_id, level).ty();
598 bug!("item {:?} with DefKind {:?}", item, def_kind);
603 // These have type privacy, so are not reachable unless they're
604 // public, or are not namespaced at all.
607 | DefKind::ConstParam
608 | DefKind::Ctor(_, _)
617 | DefKind::LifetimeParam
618 | DefKind::ExternCrate
620 | DefKind::ForeignMod
622 | DefKind::InlineConst
627 | DefKind::Generator => (),
632 impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
633 type Map = Map<'tcx>;
635 /// We want to visit items in the context of their containing
636 /// module and so forth, so supply a crate for doing a deep walk.
637 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
638 NestedVisitorMap::All(self.tcx.hir())
641 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
642 let item_level = match item.kind {
643 hir::ItemKind::Impl { .. } => {
645 Option::<AccessLevel>::of_impl(item.def_id, self.tcx, &self.access_levels);
646 self.update(item.def_id, impl_level)
648 _ => self.get(item.def_id),
651 // Update levels of nested things.
653 hir::ItemKind::Enum(ref def, _) => {
654 for variant in def.variants {
655 let variant_level = self.update_with_hir_id(variant.id, item_level);
656 if let Some(ctor_hir_id) = variant.data.ctor_hir_id() {
657 self.update_with_hir_id(ctor_hir_id, item_level);
659 for field in variant.data.fields() {
660 self.update_with_hir_id(field.hir_id, variant_level);
664 hir::ItemKind::Impl(ref impl_) => {
665 for impl_item_ref in impl_.items {
666 if impl_.of_trait.is_some()
667 || self.tcx.visibility(impl_item_ref.id.def_id) == ty::Visibility::Public
669 self.update(impl_item_ref.id.def_id, item_level);
673 hir::ItemKind::Trait(.., trait_item_refs) => {
674 for trait_item_ref in trait_item_refs {
675 self.update(trait_item_ref.id.def_id, item_level);
678 hir::ItemKind::Struct(ref def, _) | hir::ItemKind::Union(ref def, _) => {
679 if let Some(ctor_hir_id) = def.ctor_hir_id() {
680 self.update_with_hir_id(ctor_hir_id, item_level);
682 for field in def.fields() {
683 if field.vis.node.is_pub() {
684 self.update_with_hir_id(field.hir_id, item_level);
688 hir::ItemKind::Macro(ref macro_def) => {
689 self.update_reachability_from_macro(item.def_id, macro_def);
691 hir::ItemKind::ForeignMod { items, .. } => {
692 for foreign_item in items {
693 if self.tcx.visibility(foreign_item.id.def_id) == ty::Visibility::Public {
694 self.update(foreign_item.id.def_id, item_level);
699 hir::ItemKind::OpaqueTy(..)
700 | hir::ItemKind::Use(..)
701 | hir::ItemKind::Static(..)
702 | hir::ItemKind::Const(..)
703 | hir::ItemKind::GlobalAsm(..)
704 | hir::ItemKind::TyAlias(..)
705 | hir::ItemKind::Mod(..)
706 | hir::ItemKind::TraitAlias(..)
707 | hir::ItemKind::Fn(..)
708 | hir::ItemKind::ExternCrate(..) => {}
711 // Mark all items in interfaces of reachable items as reachable.
713 // The interface is empty.
714 hir::ItemKind::Macro(..) | hir::ItemKind::ExternCrate(..) => {}
715 // All nested items are checked by `visit_item`.
716 hir::ItemKind::Mod(..) => {}
717 // Handled in the access level of in rustc_resolve
718 hir::ItemKind::Use(..) => {}
719 // The interface is empty.
720 hir::ItemKind::GlobalAsm(..) => {}
721 hir::ItemKind::OpaqueTy(..) => {
722 // HACK(jynelson): trying to infer the type of `impl trait` breaks `async-std` (and `pub async fn` in general)
723 // Since rustdoc never needs to do codegen and doesn't care about link-time reachability,
724 // mark this as unreachable.
725 // See https://github.com/rust-lang/rust/issues/75100
726 if !self.tcx.sess.opts.actually_rustdoc {
727 // FIXME: This is some serious pessimization intended to workaround deficiencies
728 // in the reachability pass (`middle/reachable.rs`). Types are marked as link-time
729 // reachable if they are returned via `impl Trait`, even from private functions.
731 cmp::max(item_level, Some(AccessLevel::ReachableFromImplTrait));
732 self.reach(item.def_id, exist_level).generics().predicates().ty();
736 hir::ItemKind::Const(..)
737 | hir::ItemKind::Static(..)
738 | hir::ItemKind::Fn(..)
739 | hir::ItemKind::TyAlias(..) => {
740 if item_level.is_some() {
741 self.reach(item.def_id, item_level).generics().predicates().ty();
744 hir::ItemKind::Trait(.., trait_item_refs) => {
745 if item_level.is_some() {
746 self.reach(item.def_id, item_level).generics().predicates();
748 for trait_item_ref in trait_item_refs {
749 let mut reach = self.reach(trait_item_ref.id.def_id, item_level);
750 reach.generics().predicates();
752 if trait_item_ref.kind == AssocItemKind::Type
753 && !trait_item_ref.defaultness.has_value()
762 hir::ItemKind::TraitAlias(..) => {
763 if item_level.is_some() {
764 self.reach(item.def_id, item_level).generics().predicates();
767 // Visit everything except for private impl items.
768 hir::ItemKind::Impl(ref impl_) => {
769 if item_level.is_some() {
770 self.reach(item.def_id, item_level).generics().predicates().ty().trait_ref();
772 for impl_item_ref in impl_.items {
773 let impl_item_level = self.get(impl_item_ref.id.def_id);
774 if impl_item_level.is_some() {
775 self.reach(impl_item_ref.id.def_id, impl_item_level)
784 // Visit everything, but enum variants have their own levels.
785 hir::ItemKind::Enum(ref def, _) => {
786 if item_level.is_some() {
787 self.reach(item.def_id, item_level).generics().predicates();
789 for variant in def.variants {
790 let variant_level = self.get(self.tcx.hir().local_def_id(variant.id));
791 if variant_level.is_some() {
792 for field in variant.data.fields() {
793 self.reach(self.tcx.hir().local_def_id(field.hir_id), variant_level)
796 // Corner case: if the variant is reachable, but its
797 // enum is not, make the enum reachable as well.
798 self.update(item.def_id, variant_level);
802 // Visit everything, but foreign items have their own levels.
803 hir::ItemKind::ForeignMod { items, .. } => {
804 for foreign_item in items {
805 let foreign_item_level = self.get(foreign_item.id.def_id);
806 if foreign_item_level.is_some() {
807 self.reach(foreign_item.id.def_id, foreign_item_level)
814 // Visit everything except for private fields.
815 hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
816 if item_level.is_some() {
817 self.reach(item.def_id, item_level).generics().predicates();
818 for field in struct_def.fields() {
819 let def_id = self.tcx.hir().local_def_id(field.hir_id);
820 let field_level = self.get(def_id);
821 if field_level.is_some() {
822 self.reach(def_id, field_level).ty();
829 let orig_level = mem::replace(&mut self.prev_level, item_level);
830 intravisit::walk_item(self, item);
831 self.prev_level = orig_level;
834 fn visit_block(&mut self, b: &'tcx hir::Block<'tcx>) {
835 // Blocks can have public items, for example impls, but they always
836 // start as completely private regardless of publicity of a function,
837 // constant, type, field, etc., in which this block resides.
838 let orig_level = mem::replace(&mut self.prev_level, None);
839 intravisit::walk_block(self, b);
840 self.prev_level = orig_level;
844 impl ReachEverythingInTheInterfaceVisitor<'_, '_> {
845 fn generics(&mut self) -> &mut Self {
846 for param in &self.ev.tcx.generics_of(self.item_def_id).params {
848 GenericParamDefKind::Lifetime => {}
849 GenericParamDefKind::Type { has_default, .. } => {
851 self.visit(self.ev.tcx.type_of(param.def_id));
854 GenericParamDefKind::Const { has_default, .. } => {
855 self.visit(self.ev.tcx.type_of(param.def_id));
857 self.visit(self.ev.tcx.const_param_default(param.def_id));
865 fn predicates(&mut self) -> &mut Self {
866 self.visit_predicates(self.ev.tcx.predicates_of(self.item_def_id));
870 fn ty(&mut self) -> &mut Self {
871 self.visit(self.ev.tcx.type_of(self.item_def_id));
875 fn trait_ref(&mut self) -> &mut Self {
876 if let Some(trait_ref) = self.ev.tcx.impl_trait_ref(self.item_def_id) {
877 self.visit_trait(trait_ref);
883 impl<'tcx> DefIdVisitor<'tcx> for ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
884 fn tcx(&self) -> TyCtxt<'tcx> {
891 _descr: &dyn fmt::Display,
892 ) -> ControlFlow<Self::BreakTy> {
893 if let Some(def_id) = def_id.as_local() {
894 if let (ty::Visibility::Public, _) | (_, Some(AccessLevel::ReachableFromImplTrait)) =
895 (self.tcx().visibility(def_id.to_def_id()), self.access_level)
897 self.ev.update(def_id, self.access_level);
900 ControlFlow::CONTINUE
904 //////////////////////////////////////////////////////////////////////////////////////
905 /// Name privacy visitor, checks privacy and reports violations.
906 /// Most of name privacy checks are performed during the main resolution phase,
907 /// or later in type checking when field accesses and associated items are resolved.
908 /// This pass performs remaining checks for fields in struct expressions and patterns.
909 //////////////////////////////////////////////////////////////////////////////////////
911 struct NamePrivacyVisitor<'tcx> {
913 maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
914 current_item: LocalDefId,
917 impl<'tcx> NamePrivacyVisitor<'tcx> {
918 /// Gets the type-checking results for the current body.
919 /// As this will ICE if called outside bodies, only call when working with
920 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
922 fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
923 self.maybe_typeck_results
924 .expect("`NamePrivacyVisitor::typeck_results` called outside of body")
927 // Checks that a field in a struct constructor (expression or pattern) is accessible.
930 use_ctxt: Span, // syntax context of the field name at the use site
931 span: Span, // span of the field pattern, e.g., `x: 0`
932 def: &'tcx ty::AdtDef, // definition of the struct or enum
933 field: &'tcx ty::FieldDef,
934 in_update_syntax: bool,
940 // definition of the field
941 let ident = Ident::new(kw::Empty, use_ctxt);
942 let hir_id = self.tcx.hir().local_def_id_to_hir_id(self.current_item);
943 let def_id = self.tcx.adjust_ident_and_get_scope(ident, def.did, hir_id).1;
944 if !field.vis.is_accessible_from(def_id, self.tcx) {
945 let label = if in_update_syntax {
946 format!("field `{}` is private", field.name)
948 "private field".to_string()
955 "field `{}` of {} `{}` is private",
958 self.tcx.def_path_str(def.did)
960 .span_label(span, label)
966 impl<'tcx> Visitor<'tcx> for NamePrivacyVisitor<'tcx> {
967 type Map = Map<'tcx>;
969 /// We want to visit items in the context of their containing
970 /// module and so forth, so supply a crate for doing a deep walk.
971 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
972 NestedVisitorMap::All(self.tcx.hir())
975 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
976 // Don't visit nested modules, since we run a separate visitor walk
977 // for each module in `privacy_access_levels`
980 fn visit_nested_body(&mut self, body: hir::BodyId) {
981 let old_maybe_typeck_results =
982 self.maybe_typeck_results.replace(self.tcx.typeck_body(body));
983 let body = self.tcx.hir().body(body);
984 self.visit_body(body);
985 self.maybe_typeck_results = old_maybe_typeck_results;
988 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
989 let orig_current_item = mem::replace(&mut self.current_item, item.def_id);
990 intravisit::walk_item(self, item);
991 self.current_item = orig_current_item;
994 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
995 if let hir::ExprKind::Struct(qpath, fields, ref base) = expr.kind {
996 let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
997 let adt = self.typeck_results().expr_ty(expr).ty_adt_def().unwrap();
998 let variant = adt.variant_of_res(res);
999 if let Some(base) = *base {
1000 // If the expression uses FRU we need to make sure all the unmentioned fields
1001 // are checked for privacy (RFC 736). Rather than computing the set of
1002 // unmentioned fields, just check them all.
1003 for (vf_index, variant_field) in variant.fields.iter().enumerate() {
1004 let field = fields.iter().find(|f| {
1005 self.tcx.field_index(f.hir_id, self.typeck_results()) == vf_index
1007 let (use_ctxt, span) = match field {
1008 Some(field) => (field.ident.span, field.span),
1009 None => (base.span, base.span),
1011 self.check_field(use_ctxt, span, adt, variant_field, true);
1014 for field in fields {
1015 let use_ctxt = field.ident.span;
1016 let index = self.tcx.field_index(field.hir_id, self.typeck_results());
1017 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1022 intravisit::walk_expr(self, expr);
1025 fn visit_pat(&mut self, pat: &'tcx hir::Pat<'tcx>) {
1026 if let PatKind::Struct(ref qpath, fields, _) = pat.kind {
1027 let res = self.typeck_results().qpath_res(qpath, pat.hir_id);
1028 let adt = self.typeck_results().pat_ty(pat).ty_adt_def().unwrap();
1029 let variant = adt.variant_of_res(res);
1030 for field in fields {
1031 let use_ctxt = field.ident.span;
1032 let index = self.tcx.field_index(field.hir_id, self.typeck_results());
1033 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1037 intravisit::walk_pat(self, pat);
1041 ////////////////////////////////////////////////////////////////////////////////////////////
1042 /// Type privacy visitor, checks types for privacy and reports violations.
1043 /// Both explicitly written types and inferred types of expressions and patterns are checked.
1044 /// Checks are performed on "semantic" types regardless of names and their hygiene.
1045 ////////////////////////////////////////////////////////////////////////////////////////////
1047 struct TypePrivacyVisitor<'tcx> {
1049 maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
1050 current_item: LocalDefId,
1054 impl<'tcx> TypePrivacyVisitor<'tcx> {
1055 /// Gets the type-checking results for the current body.
1056 /// As this will ICE if called outside bodies, only call when working with
1057 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
1059 fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
1060 self.maybe_typeck_results
1061 .expect("`TypePrivacyVisitor::typeck_results` called outside of body")
1064 fn item_is_accessible(&self, did: DefId) -> bool {
1065 self.tcx.visibility(did).is_accessible_from(self.current_item.to_def_id(), self.tcx)
1068 // Take node-id of an expression or pattern and check its type for privacy.
1069 fn check_expr_pat_type(&mut self, id: hir::HirId, span: Span) -> bool {
1071 let typeck_results = self.typeck_results();
1072 let result: ControlFlow<()> = try {
1073 self.visit(typeck_results.node_type(id))?;
1074 self.visit(typeck_results.node_substs(id))?;
1075 if let Some(adjustments) = typeck_results.adjustments().get(id) {
1076 adjustments.iter().try_for_each(|adjustment| self.visit(adjustment.target))?;
1082 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1083 let is_error = !self.item_is_accessible(def_id);
1087 .struct_span_err(self.span, &format!("{} `{}` is private", kind, descr))
1088 .span_label(self.span, &format!("private {}", kind))
1095 impl<'tcx> Visitor<'tcx> for TypePrivacyVisitor<'tcx> {
1096 type Map = Map<'tcx>;
1098 /// We want to visit items in the context of their containing
1099 /// module and so forth, so supply a crate for doing a deep walk.
1100 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1101 NestedVisitorMap::All(self.tcx.hir())
1104 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
1105 // Don't visit nested modules, since we run a separate visitor walk
1106 // for each module in `privacy_access_levels`
1109 fn visit_nested_body(&mut self, body: hir::BodyId) {
1110 let old_maybe_typeck_results =
1111 self.maybe_typeck_results.replace(self.tcx.typeck_body(body));
1112 let body = self.tcx.hir().body(body);
1113 self.visit_body(body);
1114 self.maybe_typeck_results = old_maybe_typeck_results;
1117 fn visit_generic_arg(&mut self, generic_arg: &'tcx hir::GenericArg<'tcx>) {
1119 hir::GenericArg::Type(t) => self.visit_ty(t),
1120 hir::GenericArg::Infer(inf) => self.visit_infer(inf),
1121 hir::GenericArg::Lifetime(_) | hir::GenericArg::Const(_) => {}
1125 fn visit_ty(&mut self, hir_ty: &'tcx hir::Ty<'tcx>) {
1126 self.span = hir_ty.span;
1127 if let Some(typeck_results) = self.maybe_typeck_results {
1129 if self.visit(typeck_results.node_type(hir_ty.hir_id)).is_break() {
1133 // Types in signatures.
1134 // FIXME: This is very ineffective. Ideally each HIR type should be converted
1135 // into a semantic type only once and the result should be cached somehow.
1136 if self.visit(rustc_typeck::hir_ty_to_ty(self.tcx, hir_ty)).is_break() {
1141 intravisit::walk_ty(self, hir_ty);
1144 fn visit_infer(&mut self, inf: &'tcx hir::InferArg) {
1145 self.span = inf.span;
1146 if let Some(typeck_results) = self.maybe_typeck_results {
1147 if let Some(ty) = typeck_results.node_type_opt(inf.hir_id) {
1148 if self.visit(ty).is_break() {
1153 let local_id = self.tcx.hir().local_def_id(inf.hir_id);
1154 if let Some(did) = self.tcx.opt_const_param_of(local_id) {
1155 if self.visit_def_id(did, "inferred", &"").is_break() {
1160 // FIXME see above note for same issue.
1161 if self.visit(rustc_typeck::hir_ty_to_ty(self.tcx, &inf.to_ty())).is_break() {
1165 intravisit::walk_inf(self, inf);
1168 fn visit_trait_ref(&mut self, trait_ref: &'tcx hir::TraitRef<'tcx>) {
1169 self.span = trait_ref.path.span;
1170 if self.maybe_typeck_results.is_none() {
1171 // Avoid calling `hir_trait_to_predicates` in bodies, it will ICE.
1172 // The traits' privacy in bodies is already checked as a part of trait object types.
1173 let bounds = rustc_typeck::hir_trait_to_predicates(
1176 // NOTE: This isn't really right, but the actual type doesn't matter here. It's
1177 // just required by `ty::TraitRef`.
1178 self.tcx.types.never,
1181 for (trait_predicate, _, _) in bounds.trait_bounds {
1182 if self.visit_trait(trait_predicate.skip_binder()).is_break() {
1187 for (poly_predicate, _) in bounds.projection_bounds {
1188 let pred = poly_predicate.skip_binder();
1189 let poly_pred_term = self.visit(pred.term);
1190 if poly_pred_term.is_break()
1191 || self.visit_projection_ty(pred.projection_ty).is_break()
1198 intravisit::walk_trait_ref(self, trait_ref);
1201 // Check types of expressions
1202 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
1203 if self.check_expr_pat_type(expr.hir_id, expr.span) {
1204 // Do not check nested expressions if the error already happened.
1208 hir::ExprKind::Assign(_, rhs, _) | hir::ExprKind::Match(rhs, ..) => {
1209 // Do not report duplicate errors for `x = y` and `match x { ... }`.
1210 if self.check_expr_pat_type(rhs.hir_id, rhs.span) {
1214 hir::ExprKind::MethodCall(_, span, _, _) => {
1215 // Method calls have to be checked specially.
1217 if let Some(def_id) = self.typeck_results().type_dependent_def_id(expr.hir_id) {
1218 if self.visit(self.tcx.type_of(def_id)).is_break() {
1224 .delay_span_bug(expr.span, "no type-dependent def for method call");
1230 intravisit::walk_expr(self, expr);
1233 // Prohibit access to associated items with insufficient nominal visibility.
1235 // Additionally, until better reachability analysis for macros 2.0 is available,
1236 // we prohibit access to private statics from other crates, this allows to give
1237 // more code internal visibility at link time. (Access to private functions
1238 // is already prohibited by type privacy for function types.)
1239 fn visit_qpath(&mut self, qpath: &'tcx hir::QPath<'tcx>, id: hir::HirId, span: Span) {
1240 let def = match qpath {
1241 hir::QPath::Resolved(_, path) => match path.res {
1242 Res::Def(kind, def_id) => Some((kind, def_id)),
1245 hir::QPath::TypeRelative(..) | hir::QPath::LangItem(..) => self
1246 .maybe_typeck_results
1247 .and_then(|typeck_results| typeck_results.type_dependent_def(id)),
1249 let def = def.filter(|(kind, _)| {
1252 DefKind::AssocFn | DefKind::AssocConst | DefKind::AssocTy | DefKind::Static
1255 if let Some((kind, def_id)) = def {
1256 let is_local_static =
1257 if let DefKind::Static = kind { def_id.is_local() } else { false };
1258 if !self.item_is_accessible(def_id) && !is_local_static {
1259 let sess = self.tcx.sess;
1260 let sm = sess.source_map();
1261 let name = match qpath {
1262 hir::QPath::Resolved(..) | hir::QPath::LangItem(..) => {
1263 sm.span_to_snippet(qpath.span()).ok()
1265 hir::QPath::TypeRelative(_, segment) => Some(segment.ident.to_string()),
1267 let kind = kind.descr(def_id);
1268 let msg = match name {
1269 Some(name) => format!("{} `{}` is private", kind, name),
1270 None => format!("{} is private", kind),
1272 sess.struct_span_err(span, &msg)
1273 .span_label(span, &format!("private {}", kind))
1279 intravisit::walk_qpath(self, qpath, id, span);
1282 // Check types of patterns.
1283 fn visit_pat(&mut self, pattern: &'tcx hir::Pat<'tcx>) {
1284 if self.check_expr_pat_type(pattern.hir_id, pattern.span) {
1285 // Do not check nested patterns if the error already happened.
1289 intravisit::walk_pat(self, pattern);
1292 fn visit_local(&mut self, local: &'tcx hir::Local<'tcx>) {
1293 if let Some(init) = local.init {
1294 if self.check_expr_pat_type(init.hir_id, init.span) {
1295 // Do not report duplicate errors for `let x = y`.
1300 intravisit::walk_local(self, local);
1303 // Check types in item interfaces.
1304 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1305 let orig_current_item = mem::replace(&mut self.current_item, item.def_id);
1306 let old_maybe_typeck_results = self.maybe_typeck_results.take();
1307 intravisit::walk_item(self, item);
1308 self.maybe_typeck_results = old_maybe_typeck_results;
1309 self.current_item = orig_current_item;
1313 impl<'tcx> DefIdVisitor<'tcx> for TypePrivacyVisitor<'tcx> {
1314 fn tcx(&self) -> TyCtxt<'tcx> {
1321 descr: &dyn fmt::Display,
1322 ) -> ControlFlow<Self::BreakTy> {
1323 if self.check_def_id(def_id, kind, descr) {
1326 ControlFlow::CONTINUE
1331 ///////////////////////////////////////////////////////////////////////////////
1332 /// Obsolete visitors for checking for private items in public interfaces.
1333 /// These visitors are supposed to be kept in frozen state and produce an
1334 /// "old error node set". For backward compatibility the new visitor reports
1335 /// warnings instead of hard errors when the erroneous node is not in this old set.
1336 ///////////////////////////////////////////////////////////////////////////////
1338 struct ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1340 access_levels: &'a AccessLevels,
1342 // Set of errors produced by this obsolete visitor.
1343 old_error_set: HirIdSet,
1346 struct ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1347 inner: &'a ObsoleteVisiblePrivateTypesVisitor<'b, 'tcx>,
1348 /// Whether the type refers to private types.
1349 contains_private: bool,
1350 /// Whether we've recurred at all (i.e., if we're pointing at the
1351 /// first type on which `visit_ty` was called).
1352 at_outer_type: bool,
1353 /// Whether that first type is a public path.
1354 outer_type_is_public_path: bool,
1357 impl<'a, 'tcx> ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1358 fn path_is_private_type(&self, path: &hir::Path<'_>) -> bool {
1359 let did = match path.res {
1360 Res::PrimTy(..) | Res::SelfTy(..) | Res::Err => return false,
1361 res => res.def_id(),
1364 // A path can only be private if:
1365 // it's in this crate...
1366 if let Some(did) = did.as_local() {
1367 // .. and it corresponds to a private type in the AST (this returns
1368 // `None` for type parameters).
1369 match self.tcx.hir().find(self.tcx.hir().local_def_id_to_hir_id(did)) {
1370 Some(Node::Item(item)) => !item.vis.node.is_pub(),
1371 Some(_) | None => false,
1378 fn trait_is_public(&self, trait_id: LocalDefId) -> bool {
1379 // FIXME: this would preferably be using `exported_items`, but all
1380 // traits are exported currently (see `EmbargoVisitor.exported_trait`).
1381 self.access_levels.is_public(trait_id)
1384 fn check_generic_bound(&mut self, bound: &hir::GenericBound<'_>) {
1385 if let hir::GenericBound::Trait(ref trait_ref, _) = *bound {
1386 if self.path_is_private_type(trait_ref.trait_ref.path) {
1387 self.old_error_set.insert(trait_ref.trait_ref.hir_ref_id);
1392 fn item_is_public(&self, def_id: LocalDefId, vis: &hir::Visibility<'_>) -> bool {
1393 self.access_levels.is_reachable(def_id) || vis.node.is_pub()
1397 impl<'a, 'b, 'tcx, 'v> Visitor<'v> for ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1398 type Map = intravisit::ErasedMap<'v>;
1400 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1401 NestedVisitorMap::None
1404 fn visit_generic_arg(&mut self, generic_arg: &'v hir::GenericArg<'v>) {
1406 hir::GenericArg::Type(t) => self.visit_ty(t),
1407 hir::GenericArg::Infer(inf) => self.visit_ty(&inf.to_ty()),
1408 hir::GenericArg::Lifetime(_) | hir::GenericArg::Const(_) => {}
1412 fn visit_ty(&mut self, ty: &hir::Ty<'_>) {
1413 if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = ty.kind {
1414 if self.inner.path_is_private_type(path) {
1415 self.contains_private = true;
1416 // Found what we're looking for, so let's stop working.
1420 if let hir::TyKind::Path(_) = ty.kind {
1421 if self.at_outer_type {
1422 self.outer_type_is_public_path = true;
1425 self.at_outer_type = false;
1426 intravisit::walk_ty(self, ty)
1429 // Don't want to recurse into `[, .. expr]`.
1430 fn visit_expr(&mut self, _: &hir::Expr<'_>) {}
1433 impl<'a, 'tcx> Visitor<'tcx> for ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1434 type Map = Map<'tcx>;
1436 /// We want to visit items in the context of their containing
1437 /// module and so forth, so supply a crate for doing a deep walk.
1438 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1439 NestedVisitorMap::All(self.tcx.hir())
1442 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1444 // Contents of a private mod can be re-exported, so we need
1445 // to check internals.
1446 hir::ItemKind::Mod(_) => {}
1448 // An `extern {}` doesn't introduce a new privacy
1449 // namespace (the contents have their own privacies).
1450 hir::ItemKind::ForeignMod { .. } => {}
1452 hir::ItemKind::Trait(.., bounds, _) => {
1453 if !self.trait_is_public(item.def_id) {
1457 for bound in bounds.iter() {
1458 self.check_generic_bound(bound)
1462 // Impls need some special handling to try to offer useful
1463 // error messages without (too many) false positives
1464 // (i.e., we could just return here to not check them at
1465 // all, or some worse estimation of whether an impl is
1466 // publicly visible).
1467 hir::ItemKind::Impl(ref impl_) => {
1468 // `impl [... for] Private` is never visible.
1469 let self_contains_private;
1470 // `impl [... for] Public<...>`, but not `impl [... for]
1471 // Vec<Public>` or `(Public,)`, etc.
1472 let self_is_public_path;
1474 // Check the properties of the `Self` type:
1476 let mut visitor = ObsoleteCheckTypeForPrivatenessVisitor {
1478 contains_private: false,
1479 at_outer_type: true,
1480 outer_type_is_public_path: false,
1482 visitor.visit_ty(impl_.self_ty);
1483 self_contains_private = visitor.contains_private;
1484 self_is_public_path = visitor.outer_type_is_public_path;
1487 // Miscellaneous info about the impl:
1489 // `true` iff this is `impl Private for ...`.
1490 let not_private_trait = impl_.of_trait.as_ref().map_or(
1491 true, // no trait counts as public trait
1493 if let Some(def_id) = tr.path.res.def_id().as_local() {
1494 self.trait_is_public(def_id)
1496 true // external traits must be public
1501 // `true` iff this is a trait impl or at least one method is public.
1503 // `impl Public { $( fn ...() {} )* }` is not visible.
1505 // This is required over just using the methods' privacy
1506 // directly because we might have `impl<T: Foo<Private>> ...`,
1507 // and we shouldn't warn about the generics if all the methods
1508 // are private (because `T` won't be visible externally).
1509 let trait_or_some_public_method = impl_.of_trait.is_some()
1510 || impl_.items.iter().any(|impl_item_ref| {
1511 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1512 match impl_item.kind {
1513 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..) => {
1514 self.access_levels.is_reachable(impl_item_ref.id.def_id)
1516 hir::ImplItemKind::TyAlias(_) => false,
1520 if !self_contains_private && not_private_trait && trait_or_some_public_method {
1521 intravisit::walk_generics(self, &impl_.generics);
1523 match impl_.of_trait {
1525 for impl_item_ref in impl_.items {
1526 // This is where we choose whether to walk down
1527 // further into the impl to check its items. We
1528 // should only walk into public items so that we
1529 // don't erroneously report errors for private
1530 // types in private items.
1531 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1532 match impl_item.kind {
1533 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..)
1535 .item_is_public(impl_item.def_id, &impl_item.vis) =>
1537 intravisit::walk_impl_item(self, impl_item)
1539 hir::ImplItemKind::TyAlias(..) => {
1540 intravisit::walk_impl_item(self, impl_item)
1547 // Any private types in a trait impl fall into three
1549 // 1. mentioned in the trait definition
1550 // 2. mentioned in the type params/generics
1551 // 3. mentioned in the associated types of the impl
1553 // Those in 1. can only occur if the trait is in
1554 // this crate and will've been warned about on the
1555 // trait definition (there's no need to warn twice
1556 // so we don't check the methods).
1558 // Those in 2. are warned via walk_generics and this
1560 intravisit::walk_path(self, tr.path);
1562 // Those in 3. are warned with this call.
1563 for impl_item_ref in impl_.items {
1564 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1565 if let hir::ImplItemKind::TyAlias(ty) = impl_item.kind {
1571 } else if impl_.of_trait.is_none() && self_is_public_path {
1572 // `impl Public<Private> { ... }`. Any public static
1573 // methods will be visible as `Public::foo`.
1574 let mut found_pub_static = false;
1575 for impl_item_ref in impl_.items {
1576 if self.access_levels.is_reachable(impl_item_ref.id.def_id)
1577 || self.tcx.visibility(impl_item_ref.id.def_id)
1578 == ty::Visibility::Public
1580 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1581 match impl_item_ref.kind {
1582 AssocItemKind::Const => {
1583 found_pub_static = true;
1584 intravisit::walk_impl_item(self, impl_item);
1586 AssocItemKind::Fn { has_self: false } => {
1587 found_pub_static = true;
1588 intravisit::walk_impl_item(self, impl_item);
1594 if found_pub_static {
1595 intravisit::walk_generics(self, &impl_.generics)
1601 // `type ... = ...;` can contain private types, because
1602 // we're introducing a new name.
1603 hir::ItemKind::TyAlias(..) => return,
1605 // Not at all public, so we don't care.
1606 _ if !self.item_is_public(item.def_id, &item.vis) => {
1613 // We've carefully constructed it so that if we're here, then
1614 // any `visit_ty`'s will be called on things that are in
1615 // public signatures, i.e., things that we're interested in for
1617 intravisit::walk_item(self, item);
1620 fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
1621 for param in generics.params {
1622 for bound in param.bounds {
1623 self.check_generic_bound(bound);
1626 for predicate in generics.where_clause.predicates {
1628 hir::WherePredicate::BoundPredicate(bound_pred) => {
1629 for bound in bound_pred.bounds.iter() {
1630 self.check_generic_bound(bound)
1633 hir::WherePredicate::RegionPredicate(_) => {}
1634 hir::WherePredicate::EqPredicate(eq_pred) => {
1635 self.visit_ty(eq_pred.rhs_ty);
1641 fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem<'tcx>) {
1642 if self.access_levels.is_reachable(item.def_id) {
1643 intravisit::walk_foreign_item(self, item)
1647 fn visit_ty(&mut self, t: &'tcx hir::Ty<'tcx>) {
1648 if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = t.kind {
1649 if self.path_is_private_type(path) {
1650 self.old_error_set.insert(t.hir_id);
1653 intravisit::walk_ty(self, t)
1658 v: &'tcx hir::Variant<'tcx>,
1659 g: &'tcx hir::Generics<'tcx>,
1660 item_id: hir::HirId,
1662 if self.access_levels.is_reachable(self.tcx.hir().local_def_id(v.id)) {
1663 self.in_variant = true;
1664 intravisit::walk_variant(self, v, g, item_id);
1665 self.in_variant = false;
1669 fn visit_field_def(&mut self, s: &'tcx hir::FieldDef<'tcx>) {
1670 if s.vis.node.is_pub() || self.in_variant {
1671 intravisit::walk_field_def(self, s);
1675 // We don't need to introspect into these at all: an
1676 // expression/block context can't possibly contain exported things.
1677 // (Making them no-ops stops us from traversing the whole AST without
1678 // having to be super careful about our `walk_...` calls above.)
1679 fn visit_block(&mut self, _: &'tcx hir::Block<'tcx>) {}
1680 fn visit_expr(&mut self, _: &'tcx hir::Expr<'tcx>) {}
1683 ///////////////////////////////////////////////////////////////////////////////
1684 /// SearchInterfaceForPrivateItemsVisitor traverses an item's interface and
1685 /// finds any private components in it.
1686 /// PrivateItemsInPublicInterfacesVisitor ensures there are no private types
1687 /// and traits in public interfaces.
1688 ///////////////////////////////////////////////////////////////////////////////
1690 struct SearchInterfaceForPrivateItemsVisitor<'tcx> {
1692 item_def_id: LocalDefId,
1693 /// The visitor checks that each component type is at least this visible.
1694 required_visibility: ty::Visibility,
1695 has_pub_restricted: bool,
1696 has_old_errors: bool,
1700 impl SearchInterfaceForPrivateItemsVisitor<'_> {
1701 fn generics(&mut self) -> &mut Self {
1702 for param in &self.tcx.generics_of(self.item_def_id).params {
1704 GenericParamDefKind::Lifetime => {}
1705 GenericParamDefKind::Type { has_default, .. } => {
1707 self.visit(self.tcx.type_of(param.def_id));
1710 // FIXME(generic_const_exprs): May want to look inside const here
1711 GenericParamDefKind::Const { .. } => {
1712 self.visit(self.tcx.type_of(param.def_id));
1719 fn predicates(&mut self) -> &mut Self {
1720 // N.B., we use `explicit_predicates_of` and not `predicates_of`
1721 // because we don't want to report privacy errors due to where
1722 // clauses that the compiler inferred. We only want to
1723 // consider the ones that the user wrote. This is important
1724 // for the inferred outlives rules; see
1725 // `src/test/ui/rfc-2093-infer-outlives/privacy.rs`.
1726 self.visit_predicates(self.tcx.explicit_predicates_of(self.item_def_id));
1730 fn bounds(&mut self) -> &mut Self {
1731 self.visit_predicates(ty::GenericPredicates {
1733 predicates: self.tcx.explicit_item_bounds(self.item_def_id),
1738 fn ty(&mut self) -> &mut Self {
1739 self.visit(self.tcx.type_of(self.item_def_id));
1743 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1744 if self.leaks_private_dep(def_id) {
1745 self.tcx.struct_span_lint_hir(
1746 lint::builtin::EXPORTED_PRIVATE_DEPENDENCIES,
1747 self.tcx.hir().local_def_id_to_hir_id(self.item_def_id),
1748 self.tcx.def_span(self.item_def_id.to_def_id()),
1750 lint.build(&format!(
1751 "{} `{}` from private dependency '{}' in public \
1755 self.tcx.crate_name(def_id.krate)
1762 let hir_id = match def_id.as_local() {
1763 Some(def_id) => self.tcx.hir().local_def_id_to_hir_id(def_id),
1764 None => return false,
1767 let vis = self.tcx.visibility(def_id);
1768 if !vis.is_at_least(self.required_visibility, self.tcx) {
1769 let vis_descr = match vis {
1770 ty::Visibility::Public => "public",
1771 ty::Visibility::Invisible => "private",
1772 ty::Visibility::Restricted(vis_def_id) => {
1773 if vis_def_id == self.tcx.parent_module(hir_id).to_def_id() {
1775 } else if vis_def_id.is_top_level_module() {
1782 let make_msg = || format!("{} {} `{}` in public interface", vis_descr, kind, descr);
1783 let span = self.tcx.def_span(self.item_def_id.to_def_id());
1784 if self.has_pub_restricted || self.has_old_errors || self.in_assoc_ty {
1785 let mut err = if kind == "trait" {
1786 struct_span_err!(self.tcx.sess, span, E0445, "{}", make_msg())
1788 struct_span_err!(self.tcx.sess, span, E0446, "{}", make_msg())
1791 self.tcx.sess.source_map().guess_head_span(self.tcx.def_span(def_id));
1792 err.span_label(span, format!("can't leak {} {}", vis_descr, kind));
1793 err.span_label(vis_span, format!("`{}` declared as {}", descr, vis_descr));
1796 let err_code = if kind == "trait" { "E0445" } else { "E0446" };
1797 self.tcx.struct_span_lint_hir(
1798 lint::builtin::PRIVATE_IN_PUBLIC,
1801 |lint| lint.build(&format!("{} (error {})", make_msg(), err_code)).emit(),
1809 /// An item is 'leaked' from a private dependency if all
1810 /// of the following are true:
1811 /// 1. It's contained within a public type
1812 /// 2. It comes from a private crate
1813 fn leaks_private_dep(&self, item_id: DefId) -> bool {
1814 let ret = self.required_visibility.is_public() && self.tcx.is_private_dep(item_id.krate);
1816 tracing::debug!("leaks_private_dep(item_id={:?})={}", item_id, ret);
1821 impl<'tcx> DefIdVisitor<'tcx> for SearchInterfaceForPrivateItemsVisitor<'tcx> {
1822 fn tcx(&self) -> TyCtxt<'tcx> {
1829 descr: &dyn fmt::Display,
1830 ) -> ControlFlow<Self::BreakTy> {
1831 if self.check_def_id(def_id, kind, descr) {
1834 ControlFlow::CONTINUE
1839 struct PrivateItemsInPublicInterfacesVisitor<'tcx> {
1841 has_pub_restricted: bool,
1842 old_error_set_ancestry: LocalDefIdSet,
1845 impl<'tcx> PrivateItemsInPublicInterfacesVisitor<'tcx> {
1849 required_visibility: ty::Visibility,
1850 ) -> SearchInterfaceForPrivateItemsVisitor<'tcx> {
1851 SearchInterfaceForPrivateItemsVisitor {
1853 item_def_id: def_id,
1854 required_visibility,
1855 has_pub_restricted: self.has_pub_restricted,
1856 has_old_errors: self.old_error_set_ancestry.contains(&def_id),
1861 fn check_assoc_item(
1864 assoc_item_kind: AssocItemKind,
1865 defaultness: hir::Defaultness,
1866 vis: ty::Visibility,
1868 let mut check = self.check(def_id, vis);
1870 let (check_ty, is_assoc_ty) = match assoc_item_kind {
1871 AssocItemKind::Const | AssocItemKind::Fn { .. } => (true, false),
1872 AssocItemKind::Type => (defaultness.has_value(), true),
1874 check.in_assoc_ty = is_assoc_ty;
1875 check.generics().predicates();
1882 impl<'tcx> Visitor<'tcx> for PrivateItemsInPublicInterfacesVisitor<'tcx> {
1883 type Map = Map<'tcx>;
1885 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1886 NestedVisitorMap::OnlyBodies(self.tcx.hir())
1889 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1891 let item_visibility = tcx.visibility(item.def_id);
1894 // Crates are always public.
1895 hir::ItemKind::ExternCrate(..) => {}
1896 // All nested items are checked by `visit_item`.
1897 hir::ItemKind::Mod(..) => {}
1898 // Checked in resolve.
1899 hir::ItemKind::Use(..) => {}
1901 hir::ItemKind::Macro(..) | hir::ItemKind::GlobalAsm(..) => {}
1902 // Subitems of these items have inherited publicity.
1903 hir::ItemKind::Const(..)
1904 | hir::ItemKind::Static(..)
1905 | hir::ItemKind::Fn(..)
1906 | hir::ItemKind::TyAlias(..) => {
1907 self.check(item.def_id, item_visibility).generics().predicates().ty();
1909 hir::ItemKind::OpaqueTy(..) => {
1910 // `ty()` for opaque types is the underlying type,
1911 // it's not a part of interface, so we skip it.
1912 self.check(item.def_id, item_visibility).generics().bounds();
1914 hir::ItemKind::Trait(.., trait_item_refs) => {
1915 self.check(item.def_id, item_visibility).generics().predicates();
1917 for trait_item_ref in trait_item_refs {
1918 self.check_assoc_item(
1919 trait_item_ref.id.def_id,
1920 trait_item_ref.kind,
1921 trait_item_ref.defaultness,
1925 if let AssocItemKind::Type = trait_item_ref.kind {
1926 self.check(trait_item_ref.id.def_id, item_visibility).bounds();
1930 hir::ItemKind::TraitAlias(..) => {
1931 self.check(item.def_id, item_visibility).generics().predicates();
1933 hir::ItemKind::Enum(ref def, _) => {
1934 self.check(item.def_id, item_visibility).generics().predicates();
1936 for variant in def.variants {
1937 for field in variant.data.fields() {
1938 self.check(self.tcx.hir().local_def_id(field.hir_id), item_visibility).ty();
1942 // Subitems of foreign modules have their own publicity.
1943 hir::ItemKind::ForeignMod { items, .. } => {
1944 for foreign_item in items {
1945 let vis = tcx.visibility(foreign_item.id.def_id);
1946 self.check(foreign_item.id.def_id, vis).generics().predicates().ty();
1949 // Subitems of structs and unions have their own publicity.
1950 hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
1951 self.check(item.def_id, item_visibility).generics().predicates();
1953 for field in struct_def.fields() {
1954 let def_id = tcx.hir().local_def_id(field.hir_id);
1955 let field_visibility = tcx.visibility(def_id);
1956 self.check(def_id, min(item_visibility, field_visibility, tcx)).ty();
1959 // An inherent impl is public when its type is public
1960 // Subitems of inherent impls have their own publicity.
1961 // A trait impl is public when both its type and its trait are public
1962 // Subitems of trait impls have inherited publicity.
1963 hir::ItemKind::Impl(ref impl_) => {
1964 let impl_vis = ty::Visibility::of_impl(item.def_id, tcx, &Default::default());
1965 // check that private components do not appear in the generics or predicates of inherent impls
1966 // this check is intentionally NOT performed for impls of traits, per #90586
1967 if impl_.of_trait.is_none() {
1968 self.check(item.def_id, impl_vis).generics().predicates();
1970 for impl_item_ref in impl_.items {
1971 let impl_item_vis = if impl_.of_trait.is_none() {
1972 min(tcx.visibility(impl_item_ref.id.def_id), impl_vis, tcx)
1976 self.check_assoc_item(
1977 impl_item_ref.id.def_id,
1979 impl_item_ref.defaultness,
1988 pub fn provide(providers: &mut Providers) {
1989 *providers = Providers {
1991 privacy_access_levels,
1992 check_private_in_public,
1998 fn visibility(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Visibility {
1999 let def_id = def_id.expect_local();
2000 match tcx.resolutions(()).visibilities.get(&def_id) {
2003 let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
2004 match tcx.hir().get(hir_id) {
2005 // Unique types created for closures participate in type privacy checking.
2006 // They have visibilities inherited from the module they are defined in.
2007 Node::Expr(hir::Expr { kind: hir::ExprKind::Closure(..), .. }) => {
2008 ty::Visibility::Restricted(tcx.parent_module(hir_id).to_def_id())
2010 // - AST lowering may clone `use` items and the clones don't
2011 // get their entries in the resolver's visibility table.
2012 // - AST lowering also creates opaque type items with inherited visibilies.
2013 // Visibility on them should have no effect, but to avoid the visibility
2014 // query failing on some items, we provide it for opaque types as well.
2015 Node::Item(hir::Item {
2017 kind: hir::ItemKind::Use(..) | hir::ItemKind::OpaqueTy(..),
2019 }) => ty::Visibility::from_hir(vis, hir_id, tcx),
2020 // Visibilities of trait impl items are inherited from their traits
2021 // and are not filled in resolve.
2022 Node::ImplItem(impl_item) => {
2023 match tcx.hir().get_by_def_id(tcx.hir().get_parent_item(hir_id)) {
2024 Node::Item(hir::Item {
2025 kind: hir::ItemKind::Impl(hir::Impl { of_trait: Some(tr), .. }),
2027 }) => tr.path.res.opt_def_id().map_or_else(
2029 tcx.sess.delay_span_bug(tr.path.span, "trait without a def-id");
2030 ty::Visibility::Public
2032 |def_id| tcx.visibility(def_id),
2034 _ => span_bug!(impl_item.span, "the parent is not a trait impl"),
2038 tcx.def_span(def_id),
2039 "visibility table unexpectedly missing a def-id: {:?}",
2047 fn check_mod_privacy(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
2048 // Check privacy of names not checked in previous compilation stages.
2050 NamePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id };
2051 let (module, span, hir_id) = tcx.hir().get_module(module_def_id);
2053 intravisit::walk_mod(&mut visitor, module, hir_id);
2055 // Check privacy of explicitly written types and traits as well as
2056 // inferred types of expressions and patterns.
2058 TypePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id, span };
2059 intravisit::walk_mod(&mut visitor, module, hir_id);
2062 fn privacy_access_levels(tcx: TyCtxt<'_>, (): ()) -> &AccessLevels {
2063 // Build up a set of all exported items in the AST. This is a set of all
2064 // items which are reachable from external crates based on visibility.
2065 let mut visitor = EmbargoVisitor {
2067 access_levels: tcx.resolutions(()).access_levels.clone(),
2068 macro_reachable: Default::default(),
2069 prev_level: Some(AccessLevel::Public),
2074 tcx.hir().walk_toplevel_module(&mut visitor);
2075 if visitor.changed {
2076 visitor.changed = false;
2082 tcx.arena.alloc(visitor.access_levels)
2085 fn check_private_in_public(tcx: TyCtxt<'_>, (): ()) {
2086 let access_levels = tcx.privacy_access_levels(());
2088 let mut visitor = ObsoleteVisiblePrivateTypesVisitor {
2092 old_error_set: Default::default(),
2094 tcx.hir().walk_toplevel_module(&mut visitor);
2096 let has_pub_restricted = {
2097 let mut pub_restricted_visitor = PubRestrictedVisitor { tcx, has_pub_restricted: false };
2098 tcx.hir().walk_toplevel_module(&mut pub_restricted_visitor);
2099 pub_restricted_visitor.has_pub_restricted
2102 let mut old_error_set_ancestry = HirIdSet::default();
2103 for mut id in visitor.old_error_set.iter().copied() {
2105 if !old_error_set_ancestry.insert(id) {
2108 let parent = tcx.hir().get_parent_node(id);
2116 // Check for private types and traits in public interfaces.
2117 let mut visitor = PrivateItemsInPublicInterfacesVisitor {
2120 // Only definition IDs are ever searched in `old_error_set_ancestry`,
2121 // so we can filter away all non-definition IDs at this point.
2122 old_error_set_ancestry: old_error_set_ancestry
2124 .filter_map(|hir_id| tcx.hir().opt_local_def_id(hir_id))
2127 tcx.hir().visit_all_item_likes(&mut DeepVisitor::new(&mut visitor));